On Thu, 18 Jan 2024 22:54:26 GMT, Chris Plummer <cjplum...@openjdk.org> wrote:
> In PointerFinder.java we have some code to determine if a pointer is in a
> TLAB, but it only executes for the SerialGC. It should work for all GCs, so I
> moved the code out of the SerialGC block.
>
> I also cleaned up the printing in PointerLocation. java a bit so when not
> using verbose mode not as much info about the tlab address is printed. This
> is consistent with other addresses, such as java stack addresses, which is
> what I modeled this change on.
>
> It's hard to test this change since it is hard to consistently get an address
> to be in the tlab. I wrote a little test program that just sits in a loop
> doing allocations. I attached to it with clhsdb and ran the threadcontext
> command, which does a fincpc on each register. About half the time the main
> thread was suspended in a frame where some registers where pointing into the
> tlab, and I confirmed this was the case for both SerialGC and G1. Here's an
> example of one register with verbose off and verbose on:
>
> rsi: 0x000000008a5d4448: In TLAB for thread "main"
> sun.jvm.hotspot.runtime.JavaThread@0x00007ffa24029000
>
> rsi: 0x000000008a5d4448: In TLAB for thread ("main" #1 prio=5
> tid=0x00007ffa24029000 nid=25392 runnable [0x0000000000000000]
> java.lang.Thread.State: RUNNABLE
> JavaThread state: _thread_in_java
> )
> [0x000000008a5d4448,0x000000008ab724b8,0x000000008b0c0250,{0x000000008b0c0490})
>
> For testing I ran all tier1, tier2, and tier5 svc tests (still in progress)
This pull request has now been integrated.
Changeset: 7476e290
Author: Chris Plummer <cjplum...@openjdk.org>
URL:
https://git.openjdk.org/jdk/commit/7476e2905380a60c7653cb69e1afded116852785
Stats: 56 lines in 2 files changed: 25 ins; 22 del; 9 mod
8323680: SA PointerFinder code can do a better job of leveraging existing code
to determine if an address is in the TLAB
Reviewed-by: kevinw, sspitsyn
-------------
PR: https://git.openjdk.org/jdk/pull/17494
